Vitamin D, the autonomic nervous system, and cardiovascular risk

Cardiovascular disease (CVD) and vitamin D deficiency are extremely prevalent worldwide (Holick 2007; World Health Organization 2011). The potential link between vitamin D deficiency and CVD‐related death in both healthy and diseased populations is a growing area of translational research. Historically, the traditional role of vitamin D in maintaining calcium homeostasis and mineral metabolism has been extensively studied (Lieben and Carmeliet 2013). Vitamin D, via its classical genomic transcriptional activity, is known to affect the physiological function of a number of target organs such as the heart, bone, and kidneys (Lieben et al. 2011). Furthermore, as highlighted in a paper published recently in Physiological Resports (Foong et al. 2014), there appears to be a link between vitamin D deficiency and respiratory symptoms in chronic lung disease. In addition, a number of nongenomic, rapid action roles of vitamin D are now known to affect tissue function, which fall outside the traditional role of regulating mineral metabolism (Gniadecki 1998; Brown et al. 1999; Norman et al. 2002; Haussler et al. 2011). While calcium and phosphate have long been regarded as the major players in the interactions observed between mineral metabolism dysfunction and CVD‐related deaths, (Peacock 2010; Bolland et al. 2011; Brini et al. 2013), these newer nongenomic roles outside of the traditional target organs suggest that vitamin D itself may have intrinsic actions outside the realm of mineral metabolism (Gniadecki 1998; Brown et al. 1999; Norman et al. 2002; Haussler et al. 2011).Vitamin D encompasses a group of fat‐soluble prohormones which can be obtained by the body through both the skin via sunlight exposure and through intestinal absorption of dietary sources and supplements (Holick 2007). Although each source contributes to the overall maintenance of vitamin D levels, exposure to sunlight is the greatest resource for the synthesis of this prohormone in …